Improvement in the manufacture of gas for fuel



UNITED STATES lmrrqa WILLIAM ELMER, OF NEW YORK, N. Y.

IMPROVEMENT IN THE MANUFACTURE OF GAS FOR FUEL,

- ILLUMINATION, &c.

Specification forming part of Letters Patent No. 87,156, dated February 23, 1869 a'ntedated February 13, 1869.

To all whom it may concern Be it known that I, WILLIAM ELMER, of the city, county, and State of New York, have invented a new and useful Method or Process for Gasifying Fuelifor Heating Purposes, and other uses to which it may be applicable; and I do hereby declare that the following is a full, clear, and exact description of my said invention.

In order that my invention may be more fully understood, I deem it necessary to make some general remarks in regard to the composition and nature of fuel, together with the results that are produced by subjecting the various substances used as fuel to the process of distillation out of contact with the atmos phere. Whatever be the nature or form of ordinary fuel, coal, wood, or peat, it is composed mainly of the same elements. Wood and peat are composed of carbon, hydrogen, oxygen, nitrogen, water, and inorganic constituents. Coal (various kinds) contains carbon, hydrogen, oxygen, nitrogen, sulphur, and inorganic constituents. When fuel is burned in the ordinary way, a large amount of carbon escapes combustion, and is carried off by the flue in the form of smoke, free carbon, or soot, and is lost as a heat-producing agent. The loss of heat carried off by the products of combustion and otherwise is also very large. This is seen in burning bituminous coal, which, as it is ordinarily burned, has a lower heating power than anthracite coal, notwithstanding the hydrogen it contains, for the reason that a portion of the hydrocarbon vapors and the smoke or free carbon not only escape combustion, but become the vehicle for a large amount of heat, which, together with the heat contained in the products of combustion, are carried off by the flue. The loss of heat passing off by the flue from an ordinary grate-fire is about five-eighths, and that from stoves and furnaces three-eighths, of the whole amount generated by combustion. An unknown quan tity of heat is likewise expended in the conversion of hydrocarbon fuel into gases be fore combustion can occur. The compounds of oxygen in fuel reduce the actual amount of carbon and hydrogen, the very elements which alone by combustion are capable of generating heat. Nitrogen compounds also reduce both the carbon and hydrogen. The water contained in wood and peat is very objectionable on account of the heat that is nec-' essarily expended in converting the water into vapor, which also becomes a vehicle for the transmission of heat. The loss of heat occasioned by the presence of sulphur in coal is just in proportion to the amount of hydrogen and carbon entering into combination with the sulphur. The inorganic constituents constitute the ashes when fuel is burned.

Now, of all the elements constituting'fuel, hydrogen and carbon are the only substances which, in their union with oxygen by combustion, can take any part in the production of heat and while the amount of heat evolved by the former is always the same, that generated by the latter depends upon the nature of the compound produced by the combustion. When carbon is fully oxidized and converted into carbonic acid, the amount of heat generated is much greater than when it is only converted into carbonic oxide, so that carbon has two degrees of caloric power, corresponding to the two degrees of oxidation. I Y

The heat generated by the combustion of carbon into carbonic acid is 80.80 heat-units, while the heat generated by twice the weigth of carbon to carbonic oxide is 49.46 heatunits, making a loss of heat by the production of carbonic oxide of 31.34 heat-units.

In the combustion of carbon, if the supply .the production of heat'depends from the objectionable or non-available elements. To accomplish this object I employ a bench off three retorts, arranged in the usual waylthat is, two retort-s set parallel to each other over the fire-chamber, the third onedirectly over these two.

Of course any number of retorts sufficient to carry out the process may be employed and arranged in any way most convenient. The upper retort should be large, while the other two may be of the usual size.

In practice I find it more economical to divide the two parallel retorts through the center by means of a partition fitted closely to the top and bottom, by inserting it in a groove or channel extending the whole length of the retorts. This partition is provided with a flue or opening near the back end of the retort. In all other respects it is gas-tight, and makes two retorts of one having two separate lids, or only one, as most convenient.

The object of dividing the retort-s by a partition is twofold: First, by this means the proper connections of the retorts with each other can be made at the front of the bench by means of pipes attached to the mouthpieces of the retorts, instead of connecting them both at the front and back of the bench,

as would be the case were it not for these partitions; and, second, to make one retort answer the purpose of two, thus economizing both in retorts and fuel. The retorts are connected as follows: A pipe is inserted in the mouthpiece of the upper retort, and extends to and is inserted in the outer side of the mouth-pieces of one of the lower retorts, which may be called the second retort.

To the outer side of the mouth-piece of the other or third retort is connected the standpipe, or pipe for conducting the gas into the holder. The two lower retorts are connected with each other by means of a pipe inserted in the inner sides of the two mouth-piecesthat is, the sides nearest to each other.

For practical operations I would recommend a bench of six retorts instead of three, and that the retorts into which the materials tobe gasified are placed be of very large dimensions, sufficiently large to hold each half a cord of wood or a ton or more of coal or peat. During the process of gasifying fuel it is necessary to keep the retorts at a white heat, or a heat of about 2,700 Fahrenheit.

The operation of a bench of three retorts is as follows: The fuel to be gasified is placed in the large retort, where all the volatile products it contains are given off, and as fast as these products are generated they are conveyed directly into one of the retorts below, and first pass to the back end of this retort upon one side of the partition and through the flue or opening in the partition, and back on the other side of the partition, of the retort to the front, thence through the connecting-pipe into the other or third retort, and to the back end of this retort upon one side of the partition, and through the opening of the partition pass on the other side of its back'to the front of the retort.

During the passage of the volatile products through the retorts they are converted into permanent gas. The two lower retorts are filled or partially filled with carbon, which may be in the form of charcoal, anthracite coal, or other forms of carbon. The object of the carbon in the retorts is to decompose the carbonic acid formed in the process, and to convert it into carbonic oxide, which is an inflammable gas; also, to decompose the aque ous vapor and other compounds present, and to convert them into inflammable gases. In the decomposition of the volatile hydrocarbon vapors a portion of the carbon they con tain is deposited in the retorts. This carbon, together with the residue carbon in the large retort, or so much of the latter as may be desirable, may also be transformed into inflammable gases by bringing highly-heated steam in contact with the carbon. Any kind of hydrocarbon fuel may be thus gasified and used for heating purposes with great economy and convenience-as, for example, all kinds of wood, peat, bituminous and cannel coal, asph alt, petroleum and other oils, all kinds of tar, bituminous schists and shales, and other hydrocarbons, or animal and vegetable matter. The gaseous fuel may be burned in stoves, grates, heaters, and in various other ways, and for all purposes wherever artificial heat is required.

The gases produced by this process are carbonic oxide, light carbureted hydrogen, and free hydrogen--a compound of gases containing the elements necessary for the production of heat in the most convenient and economical form possible. The amountof heat evolved during the combustion of carbonic oxide into carbonic acid is nearly equal to that which would be evolved by carbon in a separate state, to'convert it into the same product-carbonic acid. The heat evolved by the combustion of carbonic oxide does not depend entirely upon the amount of oxygen which is required to convert it into carbonic acid, but mainly upon the intensity of chemical action of the combining bodies. The heating power of light carbureted hydrogen is more than double the heating power of carbonic oxide; while the quantity of heat generated by the combustion of hydrogen, producing aqueous vapors, is more than four times as great as that generated by the combustion of an equal weight of carbonic oxide or solid carbon to carbonic acid; hence hydrogen and substances containin git, produce with perfect combustion the greatest quantity of heat. To this rule there are no exceptions. Hydrogen, when uniting with oxygen, produces the highest heating power known to result froru combustion, owing to the intense chemical action and the rapidity of the combination of gases. The intense chemical action resulting from the rapid combustion of gases explains the superiority of gaseous fuel over solid fuel.

The gaseous fuel is permanent in its character, and unaffected by the temperatures of lthe atmosphere, and therefore is susceptible of being conveyed through pipes to all parts of towns and cities, the same as coal-gas, with this advantage in favor of the former, that there would be no condensation, as there is with illuminating-gas in the pipes or holder.

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The process or method of gasifying fuel by subjecting it out of contact with the atmosphere to the process of distillation, and by subjecting the distillate in several consecutive retorts to a temperature sufliciently high to convert the distilled products into permanent inflammable gases, substantially as above set forth.

2. The process or method of converting the various non-inflammable compounds produced in the process of distillation of fuel into inflammable gases, by subjecting these compounds to the action of a high heat in contact with carbon, substantially as above set forth.

3. The process of converting the various condensable compounds generated in the process of distillation of fuel into permanent inflammable gaseous compounds by means of carbon or other suitable substances, substantially as above set forth.

4. The method of dividing the retorts by means of a partition, in the manner and for the purposes specified, substantially as above set forth.

5. A combination of the various processes and means employed as a whole, for the purposes described and set forth in the foregoing specification, and this whether the means employed' for this purpose be in the precise form described by me or otherwise, so long as substantially the same results are produced.

In testimony whereof I have hereunto set my hand this 8th day of July, A. D. 1868.

WILLIAM ELMER.

Witnesses:

WILLIAM A. ELMER, CHARLES P. HARTT. 

